After the announcement on the launch of OCN and seeing how easy it was to implement a download, and also considering that we have three machines here running the highly crippled Mandrake 9.0 with hopes to solve all our troubles with 9.1, I set out to see if I could use the OCN.

The good news is that it was as easy as adding 4 lines of Javascript. The bad news was that it wasn't that easy, and now almost three days later, I'm hoping I have it licked.

The first obstacle was not really an obstacle, just an annoyance: You can't craft an OCN link, you have to craft a special page which will contain OCN links. This is because your page must first run some javascript to alert the network of your presence, and then it re-writes all links of some certain file extension to be taken from the local http proxy, the component they call the OCN client, instead of from the source. Fair enough, it does mean you can't use a program like wget to get OCN content but that's because it's a browser trick, not a new protocol (there probably is a way to use wget, maybe to localhost:8081 or something, but that's not disclosed in their site and the software comes with no docs and no console)

Anyway, fair enough, I create this page for downloading Mandrake 9.1 RC2 and click the links knowing (because I once coded software like this for OnionNetworks back when they were part of OpenCola) I have to seed the server; their lease server needs to download the same content just once to compute the hash keys needed to ensure the content integrity. Literally translated, for ISO images, that means "come back tomorrow and try again", so I did.

Only, on the next day, the download wouldn't go through: According to the error message, and confirmed by Ry4an, OCN will not download text/plain and my chosen Mandrake mirror had not set their mime-types for .iso files, so the default is ... you guessed it. Some emails back and forth with Ry4an and it turns out they don't dare do otherwise because of the security model in MSIE, so if the server says text/plain, OCN is going to reject it. How much of a show-stopper is this? I had to try half a dozen Mandrake mirrors before I found one that used the right HTTP headers!

That's probably bad news for OCN: It's not as easy as adding 4 lines of script, you must also test the download of the desired content to see if the right headers come back, and if they don't, you have to lobby the host site to fix it (good luck with that!). Of course knowing the text/plain prohibition up front would have saved me a lot of bother ...

Long story short, I've now set OCN on the Mandrake ISO's from one of the very few properly configured mirrors, and, well, OCN is building it's hash trees, so all I can do now is wait until morning and try again ...